Conventionally, an example of a high-pressure dome type scroll compressor is disclosed in Japanese Patent Laid-Open Publication No. HEI 5-79475. The scroll compressor disclosed in the above publication is a co-rotational type scroll compressor having a driven scroll which rotates in accordance with a rotating motion of a drive scroll. The co-rotational type scroll compressor has a construction as shown in FIG. 2 in which the inside of a vertical type hermetic casing A is separated into upper and lower hermetic sections by a partition wall P, thereby forming a motor chamber A1 and a compressing chamber A2 in the upper and lower sections, respectively. Then, a motor B is installed in the motor chamber A1, while a co-rotational type scroll compressor C is installed in the compressing chamber A2. The scroll compressor C is comprised of a drive scroll E which is formed at an end of a drive shaft D connected to the motor B, and a driven scroll G which has a driven shaft F and is driven in accordance with the drive scroll E. The drive shaft D is rotatably supported at a pipe-shaped first bearing section H formed upright at the partition wall P, i.e., a bottom wall of the motor chamber A1, while the driven shaft F is rotatably supported at a pipe-shaped second bearing section I formed upright in a position located eccentrically with respect to the first bearing section H at a bottom wall of the compressing chamber A2. Further, the drive shaft D is formed internally axially with a high-pressure gas discharge passage D1 which extends vertically. A lower portion of the discharge passage D1 communicates with a discharge outlet E1 provided at a center portion of the drive scroll E, while an upper portion of the discharge passage D1 is opened to the motor chamber A1. Further, an outward discharge pipe J is opened in a position at a side of the opening of the discharge passage D1 on the upper side of the motor chamber A1, while an intake pipe K is opened at the compressing chamber A2.
When, the drive scroll E is rotatively operated via the drive shaft D upon rotation of the motor B, with which the driven scroll G is rotated in accordance with the rotation of the drive scroll E with the driven shaft F rotatably supported at the second bearing section I. Thus, the introduced gas, which has been introduced from the intake pipe K into the compressing chamber A2, is inhaled into the compressing chamber formed between both the scrolls E and G, and then compressed. The compressed gas is discharged from the discharge outlet E1 via the discharge passage D1 into the motor chamber A1, and then discharged outwardly from the discharge pipe J opened at the motor chamber A1.
However, in the above-mentioned compressor, the outward discharge pipe J is opened near the opening of the discharge passage D1 in the position at the side of the opening of the discharge passage D1 on the upper side of the motor chamber A1. Therefore, most of the gas discharged from the discharge passage D1 into the motor chamber A1 is disadvantageously discharged directly to the outside from the discharge pipe J. Therefore, when the discharge gas passes through the discharge passage D1, a center portion of a rotor B1 of the motor B can be cooled by the discharge gas. However, the effect of cooling the motor B by the discharge gas can not be expected at a stator B2 of the motor B and a peripheral portion of the rotor B1 which generate a great amount of heat. The above-mentioned disadvantage will eventually cause a temperature increase of the motor B, resulting in a problem regarding the reduction in the reliability and efficiency of the motor B and a problem regarding the oil mixed in the discharge gas being directly discharged outside the casing to cause oil shortage.
It is an object of the present invention to provide a scroll compressor capable of fully exerting the effect of cooling the motor by the discharge gas so as to prevent the possible temperature increase of the motor and allow the motor to have increased reliability and efficiency, and satisfactorily separating the oil mixed in the discharge gas.